独立着色和旋转3D VTK图示符

Question

我尝试使用pythonwrapper for VTK在一个场景中显示多个glyph，每个glyph都有自己的颜色和旋转。不幸的是，vtk只考虑了旋转（使用vtkTensorGlyph）。相反，当我使用vtkGlyph3D时，只考虑颜色。在

下面是一段带有vtkTensorGlyph的现成代码。每个立方体应该有一个随机的颜色，但是它们都是相同的颜色。我反复阅读了VTK的文档，但没有找到任何解决方案。在

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import vtk
import scipy.linalg as sc
import random as ra
import numpy as np
import itertools

points = vtk.vtk.vtkPoints()  # where to locate each glyph in the scene
tensors = vtk.vtkDoubleArray() # rotation for each glyph
tensors.SetNumberOfComponents(9)
colors = vtk.vtkUnsignedCharArray() # should be the color for each glyph
colors.SetNumberOfComponents(3)

# let's make 10 cubes in the scene
for i in range(0, 50, 5): 
    points.InsertNextPoint(i, i, i) # position of a glyph
    colors.InsertNextTuple3(ra.randint(0, 255), ra.randint(0, 255), ra.randint(0, 255) ) # pick random color
    rot = list(itertools.chain(*np.reshape(sc.orth(np.random.rand(3, 3)).transpose(), (1, 9)).tolist())) # random rotation matrix (row major)
    tensors.InsertNextTuple9(*rot)

polydata = vtk.vtkPolyData() # create the polydatas
polydata.SetPoints(points) 
polydata.GetPointData().SetTensors(tensors)
polydata.GetPointData().SetScalars(colors)

cubeSource = vtk.vtkCubeSource()
cubeSource.Update()

glyphTensor = vtk.vtkTensorGlyph()
glyphTensor.SetColorModeToScalars() # is it really work ?

try:
    glyphTensor.SetInput(polydata)
except AttributeError:
    glyphTensor.SetInputData(polydata)

glyphTensor.SetSourceConnection(cubeSource.GetOutputPort())
glyphTensor.ColorGlyphsOn() # should not color all cubes independently ?
glyphTensor.ThreeGlyphsOff()
glyphTensor.ExtractEigenvaluesOff()
glyphTensor.Update()

# next is usual vtk code
mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(glyphTensor.GetOutputPort())

actor = vtk.vtkActor()
actor.SetMapper(mapper)

ren = vtk.vtkRenderer()
ren.SetBackground(0.2, 0.5, 0.3)
ren.AddActor(actor)

renwin = vtk.vtkRenderWindow()
renwin.AddRenderer(ren)
iren = vtk.vtkRenderWindowInteractor()
iren.SetInteractorStyle(vtk.vtkInteractorStyleTrackballCamera())
iren.SetRenderWindow(renwin)

renwin.Render()
iren.Initialize()
renwin.Render()
iren.Start()

Answer 1

您可以按以下方式为vtktensorglyph涂上不同的颜色。我会用不同颜色的张量字形来展示我的C++代码的一些片段。我希望您可以将类似的东西集成到您的python代码中：

vtkSmartPointer<vtkFloatArray> colors = vtkSmartPointer<vtkFloatArray>::New();
vtkSmartPointer<vtkPolyData> data = vtkSmartPointer<vtkPolyData>::New();

//Add for each single object the following data to colors: 
float color[3] = {r, g, b};
colors->InsertNextTupleValue(color);

//Then proceed here after adding all colors
colors->SetName("colors");
colors->SetNumberOfComponents(3);

//Add all necessary information to the vtkPolyData element, including the color information
data->GetPointData()->SetScalars(colors);

...

tensorGlyph->SetInputData(data);
tensorGlyph->ColorGlyphsOn();
tensorGlyph->SetColorModeToScalars();

虽然VTK开发人员可能打算使用RGB元组来定义颜色，但只需使用第一个参数“r”。在[0,1]的间隔内改变“r”将导致不同的颜色。在

使用VTK 6.1.0